cdgraff at gmail
Dec 7, 2011, 6:13 AM
Post #4 of 4
Thanks guys for the answers...
I try to create, Active/Active model... I'll check this soft like wackamole
2011/12/7 john [at] 8t8 <john [at] 8t8>
> I'm succesfully using lvs in director mode to load balance and provide ha
> for multiple varnish caches. It works really well.
> On Dec 7, 2011 5:36 a.m., "Allan Wind" <allan_wind [at] lifeintegrity>
>> On 2011-12-07 00:05:24, Alejandro wrote:
>> > Hi guys,
>> > I need your advice... I'm using varnish into multiple server, some for
>> > caching dynamic content and other only for static content.
>> > On front of the Dynamic Content Varnish y have Cisco ACE Load balancer,
>> > on front of the Static Varnish, the traffic is much higher and can't use
>> > Cisco ACE, for this reason I'm using RoundRobin DNS into this 2 servers.
>> > This week I had, some network issue with one of this servers and when
>> > network go down I loose 50% of the traffic...
>> > here my question, or advice request... How I can have HA with 2 varnish
>> > server? I'm thinking on Heartbeat or Heartbeat+ldirectord, please fell
>> > to send your suggestions.
>> As your clients do not fall back to the 2nd IP it means you need
>> one (active/passive) or two vips (active/active) that can be
>> shared between your two varnish servers.
>> If you have cachable dynamic content then your two Varnish
>> instances may return different content to the same client. This
>> may or may not be an issue. Others will have to weight in if
>> cache invalidation of Varnish entries is a doable strategy
>> (if you cannot set your expiration headers correctly). On the
>> positive side you have a warm cache should one of your Varnish
>> instances fail. With a active/passive fail over the cold cache
>> may be problematic.
>> That said I am surprised that you think Varnish will be able to
>> handle your traffic but a pair of load balancers cannot. If the
>> Cisco ACE is not up to it have you looked at haproxy? You still
>> have the same vip issues, but load balancers are stateless and
>> give you persistence connections to minimize differences between
>> Varnish instances.
>> Allan Wind
>> Life Integrity, LLC
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>> varnish-misc [at] varnish-cache
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